Preparation and Thermal Performance of Silica/n-Tetradecane Microencapsulated Phase Change Material for Cold Energy Storage

Abstract

A novel silica (SiO2)/n-tetradecane microencapsulated phase change material (MEPCM) was synthesized by in situ interfacial polycondensation. The influences of the amount of the composite emulsifier and the mass ratio of n-tetradecane and tetraethyl silicate on the MEPCM performance were systematically investigated. The morphology, chemical structure, and composition of the MEPCM were characterized by scanning electron microscopy and energy dispersive X-ray spectrometer, Fourier transform infrared spectroscopy, and X-ray diffraction, and its thermal performance and thermal stability were measured by differential scanning calorimetry and thermogravimetric analysis. The results showed that the n-tetradecane core material was successfully encapsulated by silica shell material with encapsulation ratio of 62.04%. The MEPCM had a melting enthalpy of 140.5 kJ kg–1 and thermal conductivity of 0.139 W m–1 K–1. Because of its excellent thermal performance and thermal stability, silica/n-tetradecane MEPCM displays a good potential for cold energy storage.

Intelligent Temperature-Control of Drilling Fluid in Natural Gas Hydrate Formation by Nano-Silica/Modified n-Alkane Microcapsules

“…However, the emulsion droplets formed were easy to break under low dosage, and the subsequent SiO 2 deposition would be blocked under high dosage; both phenomena restricted the effective coating of nano-silica shell. A slight increase in the ratio of Tween 80 may result in the increase of the Hydrophile Lipophilic Balance (HLB) value, which makes the droplets more stable in O/W emulsion [ 30 ]. In the case that the core/shell ratio is large, nano-silica produced by hydrolysis and polycondensation will not be sufficient to completely cover the core material, resulting in the breakage of some microcapsules; while small core/shell ratio may lead to a shell that is too thick.…”

Synthesis and properties of microencapsulated phase change material with a urea–formaldehyde resin shell and paraffin wax core

“…The microencapsulation increased the area of heat conduction of paraffin wax, and the smaller particle size of Micro‐P6 lead to the larger heat conduction area. The thermal conductivity of Micro‐P6 could be further improved by nano‐SiO 2 , because the thermal conductivity of nano‐SiO 2 is better than polymers or paraffin …”

Expanded Graphite/Paraffin/Silicone Rubber as High Temperature Form-stabilized Phase Change Materials for Thermal Energy Storage and Thermal Interface Materials

“…Therefore, the silicone rubber has a good thermal stability that can be a good supporting material for PW. As for pure PW, the absorption peaks can be seen at 2918 cm −1 (-CH 2 symmetric stretching vibration), 2849 cm −1 (-CH 3 symmetric stretching vibration), 1466 cm −1 (-CH 2 bending vibration) and 722 cm −1 (-CH 2 rocking vibration) [4,23]. For the EG/PW/SR composite, all of the corresponding characteristic peaks of PW and SR are presented, without appearing new peaks.…”

“…One important material for thermal energy storage is a phase-change material (PCM), which can absorb and release a large amount of thermal energy during the phase change process (solid-liquid, solid-solid and liquid-gas). Due to their high energy storage density and nearly isothermal operating characteristic, PCMs have been widely used in solar energy, industrial waste heat recover, building and battery management [3][4][5]. According to the different working modes and structures, the systems of PCM in solar energy and industrial waste heat recovery can be divided into two types, one is heat pipe heat exchanger and the other is the regenerative phase change energy storage system.…”

“…The other is to microencapsulate PW into core/shell structures. Various types of core and shell materials have been widely explored, including graphene [17,18], polymer shells of PMMA [19], PS [20] and PU [21], and inorganic shells of SiO 2 [4,[22][23][24][25] and CaCO 3 [26], etc. In general, the liquid leakage issue of PW can be effectively prevented by utilizing the compatibility between a polymer and PW, as the polymeric matrix can fix PW by a strong intermolecular force, therefore suppressing PW leaching [27,28].…”